Method of separating ores by treatment with a gaseous polyhalosilane



Aug. 14, 1951 K. F. SCHEU 2,564,546

METHOD OF SEPARATING ORES BY TREATMENT WITH A GASEOUS POLYHALOSILANE Filed July 23, 1947 INVENTOR. MEL E SCHEU.

16, AT TORNEYS.

Patented Aug. 14, 1951 DIETHOD F SEPARATING ORES BY TREAT- DIENT WITH A GASEOUS POLYHALOSIL- Karl I. Scheu, Lakewood, Ohio, assignor to Car-1H. Scheu, Lakewood, Ohio Application July 23, 1947, Serial No. 783,105

18 Claims.

This invention relates to an improved process or method of treating ore whereby to more economically separate the ore from siliceous gangue material with which it is associated as it comes from the mine.

It is an object of my invention to separate ores economically from gangue material by treating the ore in such manner as to render the particles thereof hydrophobic.

Another object of the invention consists in the ability to separate ores having relatively close specific gravities from a mass including siliceous gangue and from each other by controlling the degree of hydrophobic treatment of the particles of the mass.

Another object consists in a process or method of the above named character which not only is economical in time and cost, but which requires only inexpensive equipment in carrying out the same, thereby making it desirable to carry out the process at the mine rather than to transport the mass to some distant or central point for treatment as in the present practice.

A further object of the invention is the production of a useful by-product.

A still further object is the elimination of the use of surface tension oils as in the flotation process, and the elimination of relatively expensive chemical treatments as have been the custom in this art.

Another object consists in the ability to carry out my process at the mine, thus making it unnecessary to transport these ores to some remote point for concentration and subsequent separation by precipitation or other methods.

Other objects and advantages of this invention will become more apparent as the following description of an embodiment of the same progresses, reference being made to the accompanying drawing in which like reference characters are employed to designate like parts throughout the same.

In the drawing, the figure is a diagrammatic view of an apparatus which may be employed in carrying out my improved method or process.

In the mining of ores, particularly metallic ores, it has been customary, first to transport the ore including the gangue material to some remote point and then to crush this mass for concentration, reduction or separation by any of the well known chemical or flotation processes. The equipment required to carry out these processes is costly, bulky and, of necessity, is usually located at some distant or central point with respect to the mine or mines to which the ore must be transported. Furthermore, these methods or processes are not too efllcient and are costly to carry out.

By my invention, the ore and gangue in its natural state may be crushed or ground at the mine to a mesh best suitable for the material at hand. By way of example, in treating a gold ore containing siliceous gangue, a screen mesh of about 40 may be employed, while in treating other materials the mesh may vary from about 10 to depending upon the nature of the materials to be treated.

According to this invention, the ground or crushed mixture of ore and gangue may then be treated to render the particles thereof hydrophobic to a degree best suited for the materials to be separated.

I have found that the particles of the mass may be rendered hydrophobic by exposing them in intimate contact to a gas or vapor of any one of the following or similar materials: Phenyl-trichlorsilane, methyl-trichlorsilane, ethyl-trichlorsilane, or diethyl-dichlorsilane.

It is to be understood that I do not limit myself to these specific materials inasmuch as the invention contemplates the use of any material which will, in the gaseous or vaporous state, render the materials to be treated hydrophobic when brought into contact with the gas or vapor.

I have illustrated in the drawing, in a diagrammatic showing, a form of apparatus which may be employed to carry out the treatment of ore and gangue or other mixtures of materials having somewhat different specific gravities, to render the same hydrophobic.

A tank I having a division plate 2 is divided into two separate compartments 3 and 4 which are adapted to be supplied with water to a level as indicated at 5 by any suitable means.

A gas chamber comprising an upright tube 6 projects at its bottom open end into the compartment 3 and below the water line 5, there being provided near the upper open end of the tube a transverse screen 1 of suitable mesh upon which the crushed ore and gangue mixture is discharged as at 8 as it comes from a crusher (not shown).

A control valve 9 is provided to control the flow of a gas such as those disclosed above, out of the gas chamber below the screen and into a discharge line H), while a gas inlet pipe for the tube 8 is provided at H, preferably near the lower end of the tube but above the water level 5.

Similarly, there is provided a gas chamber l2 comprising a tube-like structure having its open bottom end extending below the water level in concentration gas chamber" while the chamber 6 10 may be referred to as a lower concentration gas chamber.

For instance, one simple example of my improved method or process of separation, may be described as follows: it being understood that the same is not limited to the specific materials, screen mesh, or gas or vapor contacting period, since by varying the mesh and the period of contact between the materials to be treated and the gas or vapor, or by varying the degree of concentration in the gas or vapor chambers, a predetermined degree of hydrophobic treatment and resultant separation is accomplished.

In the event, for instance, it is desired to separate metallic silver, tungsten and silicious matter, contained in an ore, the crushed ore and gangue is first deposited upon the screen I of proper mesh as indicated at 8 and the particles are caused to pass therethrough and, by gravity,

longitudinally through the gas chamber 6 and the lower concentration of gas therein. The screen tends to disperse or spread the mixed particles so that in passing through the body of gas in the chamber 6 they will be brought into intimate contact with the gas and rendered hydrophobic to the desired degree.

The treated particles are deposited into the body of water in the compartment 3 and, due to their having been rendered hydrophobic by the action of the gas through which they have passed,

the lighter particles such as the siliceous matter will rise to-the surface of the water, while the heavier particles of silver and tungsten even though subjected to a limited hydrophobic treatment, will fall upon the traveling agitator and 4 conveyor belt IS. The agitator and conveyor comprising a pair of sprockets or pulleys ll, one of which is driven, and an endless belt-type agitator l8 driven by said sprockets or pulleys.

The agitator is located below the water level in the compartment 3 and while operating tends to keep the water and particles of ore and gangue deposited thereon in an agitated condition, thus further releasing those lighter hydrophobic gangue particles carried to the agitator by the heavier particles so that they may float on the water surface.

A conveyor comprising a driven belt l9 having a plurality of buckets thereon is disposed at its lower end beneath the agitator and serves to catch the heavier particles released by the agitator and to elevate them from the body of water in the compartment 3 and deposit them upon a slide 2| whereupon the particles are dropped upon the screen IS in the tube l2. The floating gangue may be skimmed from the surface of the water in any convenient manner. As the particles are caused to pass through the screen l3 and drop into the water contained in the compartment 4 they again are dispersed and passed further hydrophobic action by the gas under concentrated conditions before they are deposited into the body of water in the compartment 4.

An agitator 22 submerged below the water line in the compartment 4 and below the gas chamber, operates to receive the heavier particles and to keep the water in a complete state of agitation. while the more buoyant particles will rise to the water surface where they may be removed. Since, in this instance, the specific gravity of silver is less than that of tungsten and effective separation of these materials under substantially the same degree of hydrophobic treatment is easily and quickly accomplished, the relatively more buoyant silver particles rise to th surface while the heavier tungsten particles are deposited upon a conveyor 23 by which means they are removed from the water and discharged in a separate pile over the discharge chute 24.

By regulating one or both of the valves 9 and- IE to control the concentration of gas or vapor to be contained in the chamber l2 and the chamber 6, it will be understood that the degree of hydrophobic action on the particles passing through these chambers may be predetermined.

Furthermore, by predetermining the distance the particles must travel through the gas in the chambers from the screens to the water surface,

and thereby controlling the elapsed time of contact with the gas or vapor, the extent of hydrophobic treatment may be regulated.

I have found by actual tests that materials such as ores, metallic ores, metallic oxides or salts, mechanical mixtures of metal chips or particles, gangue, water soluble materials and many other substances having different specific gravities can eiiiciently and inexpensively be separated from a mass containing two or more of such materials, by the hydrophobic treatment disclosed herein.

It appears that when the particles of material are brought into contact with the gas or vapor of the class disclosed herein, even for a very short time period, say a fraction of a second, a water repellant coating envelops these particles, possibly occluding some gas pockets within the coating or in the interstices of the particles to the extent that the particles become relatively buoyant. I have found this to be indicated in exposing silica particles to contact with a gas of the group identified above, wherein the particles were dropped through a gas filled chamber for a distance of but 15", the gas employed being methyltrichlorsilane. During this short period of contact at room temperature the particles were rendered sufllciently hydrophobic to cause them to cling tenaciously to the surface of the body of water into which they were dropped. It was then a relatively easy matter to skim these hydrophobicly treated particles from the water surface.

Mixed with the particles of silica were particles of a material having a greater specific gravity than that of silica. These particles were subjected to the same treatment simultaneously along with the silica particles and, being of a greater specific gravity sank below the surface of the water even though they were hydrophobicly treated.

As indicated in the drawing, it will be seen that where a mixture contains three materials to be separated, the mixture may be run through the apparatus as described above and it will be apparent that the material having the lesser specific gravity will be separated first in the tank 3 and will be floated upon the surface of the water in that tank, the two remaining and partially treated materials to be separated will be passed through higher concentration gas chamber I: where further hydrophobic treatment will cause a separation of these two materials, the lighter arising to the surface of the water in the tank 4 while the heavier will be conveyed by the conveyor 23 into a separate pile outside the tank.

While I have shown a two-stage apparatus in the drawing it is obvious that the invention contemplates the use of a single stage only where .two materials are to be separated from one another, and that additional stages may be added if more than three materials are to be separated.

From the above, it will be understood that a by-product consisting of the hydrophobic siliceous particles may be recovered and used for many purposes, such as abrasives, fillers and insulators. This by-product. by its ability to resist absorption of moisture, makes an excellent material for use in the manufacture of fillers and insulators.

I claim:

1. The process of treating a crushed ore comminuted to a particle size of between about and 60 mesh to separate metallic silver, tungsten and siliceous matter contained therein which consists in sifting the particles through a first zone of gaseous polyhalosilane, introducing the particles below the surface of a body of water where by having been rendered hydrophobic the treated particles of siliceous matter are forced to the surface to be skimmed oil and the particles of silver and tungsten sink; sifting the mixture of silver and tungsten particles through a second zone of gaseous polyhalosilane of greater concentration than in said first zone, introducing the particles below the surface of a body of water where by having been rendered hydrophobic the treated particles of silver are forced to the surface to be skimmed off and the tungsten particles sink.

2. The process of treating a crushed ore comminuted to a particle size of between about 10 and 60 mesh to separate metallic silver, tungsten and siliceous matter contained therein which consists in sifting the particles through a first zone of polyhalosilane gas, introducing the particles below the surface of a body of water where the particles of siliceous matter are forced to the surface to be skimmed oil and the particles of silver and tungsten sink: sifting the mixture of silver and tungsten particles through a second zone of gaseous polyhalosilane. introducing the particles below the surface of a body of water where the particles of silver are forced to the surface to be skimmed off and the tungsten particles sink.

3. The process of separating comminuted tungsten, silver, and siliceous matter from a mixture containing the same, which consists in sifting the particles of the mixture through a first zone of gaseous methyl trichlorsilane, introducing said particles into a body of water, whereby the particles of siliceous matter are forced to the surface of the water and separated from the tungsten and silver particles, subsequently sifting the particles of tungsten and silver through a second zone of gaseous methyl trichlorsilane of greater concentration than in said first zone, introducing said particles into a body of water, whereby the particles of silver are forced to the surface of the water and separated from the tungsten particles.

4. The process of treating a comminuted mass of ore to separate metallic silver, tungsten and siliceous matter contained therein, which con- 6 stats in sifting the particles through a first zone of gaseous polyhalosilane, introducing the particles below the surface of a body of water where by having been rendered hydrophobic the lighter particles of siliceous matter are forced to the surface to be skimmed oil and the heavier particles of silver and tungsten sink, sifting the mixture of silver and tungsten particles through a second zone of gaseous polyhalosilane of greater concentration than in said first zone, introducing the particles below the surface of a body of water where by having been rendered hydrophobic the lighter particles of silver are forced to the surface to be skimmed off and the heavier particles of tungsten sink.

5. The process of treating ore and associated siliceous gangue comminuted to a particle size of between about 10 and 60 mesh to separate the ore from the gangue, which consists in sifting the particles through a zone of gaseous methyl trichlorsilane. subsequently introducing the treated particles below the surface of a body of water where by having been rendered hydrophobic the particles of gangue are forced to the surface to be skimmed oil and the heavier ore particles sink.

6. The process of treating ore and associated siliceous gangue comminuted to particle size to separate the ore from the gangue which consists in sifting the particles through a zone of gaseous polyhalosilane, introducing the treated particles below the surface of a body of water whereby having been rendered hydrophobic the lighter particles of gangue are forced to the surface and separated from the heavier ore particles.

7. The process of treating ore and associated siliceous gangue comminuted to a particle size of between about 10 and 60 mesh to separate the ore from the gangue which consists in sifting the comminuted material through a zone of gaseous polyhalosilane, subsequently introducing the particles below the surface of a body of water where by having been rendered hydrophobic the gangue particles having a lesser specific gravity are forced to the surface to be skimmed oil and the ore particles having a greater specific gravity sink.

8. The process of treating a comminuted mixture of silver and tungsten to separate the tungsten particles of greater specific gravity from the silver particles of lesser specific gravity which consists in sifting the particles through a zone of gaseous polyhalosilane, introducing the particles below the surface of a body of water where by having been rendered hydrophobic the silver .particles are forced to the surface of the water to be skimmed off and the tungsten particles sink.

9. The process of claim 8 wherein the polyhalosilane gas is methyl trichlorsilane.

10. The process of claim 9 wherein the mixture of silver and tungsten is comminuted to a particle size of between about 10 and 60 mesh.

11. The process of separating silver and tungsten comminuted in a mixture to a particle size of between about 10 and 60 mesh, which consists in sifting the particles of the mixture through a zone of gaseous polyhalosilane, introducing the particles below the surface of a body of water, whereby having been rendered relatively more hydrophobic the particles of silver are forced to the surface of the water and separated from the particles of tungsten.

12. The process of separating comminuted silver and tungsten, which consists in sifting the particles of the mixture through a zone of gaseous polyhalosilane, introducing the particles below the surface of a body of water, whereby having 7 been rendered relatively more hydrophobic the particles of silver are forced to the surface of the water and separated from the particles of tun sten.

13. The process of treating a comminuted mixture of metals to separate the particles of greater specific gravity from the particles of lesser specific gravity, which consists in sifting the particles through a. zone of gaseous =polyhalosilane, introducing the particles below the surface of a body of water where by having been rendered hydrophobic the particles of lesser specific gravity are forced to the surface of the water and separated from the particles of greater specific gravity.

14. The process of claim 13 wherein the mixture of metals is comminuted to a particle size of between about 10 and 60 mesh.

15. The process of treating a mixture of .pulverized metals having different specific gravities to separate the lighter from the heavier which consists in sifting the particles through a zone of polyhalosilane gas, subsequently introducing said particles below the surface of a body of water whereby having been rendered hydrophobic the lighter particles rise to be skimmed oil? and the heavier particles sink.

16. The process of treating to separate a mixture of metal ores having relatively close specific gravities comminuted to a particle size of between about 10 and 60 mesh which consists in siftin the comminuted mixture through a zone of gaseous polyhalosilane, introducing the particles into a body of water below the surface thereof, where by having been rendered hydrophobic the particles of material of lesser specific gravity are forced to the surface of the body of water and the particles of material of greater specific gravity sink.

KARL F. SCHEU.

REFERENCES CITED The following references are of record in the the oi. this patent:

UNITED STATES PATENTS 

16. THE PROCESS OF TREATING TO SEPARATE A MIXTURE OF METAL ORES HAVING RELATIVELY CLOSE SPECIFIC GRAVITIES COMMINUTED TO A PARTICLE SIZE OF BETWEEN ABOUT 10 AND 60 MESH WHICH CONSISTS IN SIFTING THE COMMIUNUTED MIXTURE THROUGH A ZONE OF GASEOUS POLYHALOSILANE, INTRODUCING THE PARTICLES INTO A BODY OF WATER BELOW THE SURFACE THEREOF, WHERE BY HAVING OF MATERIAL OF LESSER SPECIFIC GRAVITY ARE FORCED TO THE SURFACE OF THE BODY OF WATER AND THE PARTICLES OF MATERIAL OF GREATER SPECIFIC GRAVITY SINK. 